mailbags

Mailbags are durable containers used by postal services and private couriers to collect, transport, and store mail and small parcels. They come in a range of sizes, from compact bags for local drop-offs to large sacks capable of holding hundreds of letters. Materials commonly include canvas, heavy-duty nylon, and other weather-resistant fabrics; many modern bags feature reinforced seams, waterproof linings, and abrasion-resistant bottoms. Some bags are color-coded by service or route to aid sorting and handling, and many carry identification numbers or labels for tracking.

Design features typically include secure closures such as drawstrings, zippers, or flap covers, along with reinforced handles and sometimes detachable shoulder straps. Security elements are common, including tamper-evident seals, serial numbers, locking clasps, and wire or metal seals to protect contents during transit. Inside, bags may have dividers or pockets to assist sorting and temporary separation of different classes of mail.

Usage and operations: Mailbags are used at collection points, post offices, and sorting facilities and are transported via mail carts, containers, aircraft, ships, or trains to regional facilities or delivery offices. The chain of custody is maintained through seals and accompanying documentation, with bags typically rotated or replaced at regular intervals, such as at shift changes or end-of-day processing. Weatherproofing and durability are important considerations to protect contents during outdoor handling and various transit conditions.

Variants and terminology: The term mail sack or mail bag is common in some regions; differences are primarily in size, closure type, and security features rather than core function. The practice and equipment have evolved with changes in logistics and security requirements.